Persistent Current in an Artificial Quantum Dot Molecule

TL;DR

This paper predicts the existence of persistent currents in 2D semiconductor quantum dot arrays influenced by magnetic flux, highlighting their dependence on interactions and disorder, and linking to quantum phase transitions.

Contribution

It introduces an exact diagonalization approach to demonstrate persistent currents in quantum dot arrays without boundary conditions, connecting to quantum phase transitions.

Findings

Persistent current exists in isolated arrays without periodic boundaries.

Persistent current depends on interactions and disorder.

The results relate to Anderson-Mott-Hubbard quantum phase transitions.

Abstract

Using an exact diagonalization technique within a generalized Mott-Hubbard Hamiltonian, we predict the existence of a ground state persistent current in coherent two-dimensional semiconductor quantum dot arrays pierced by an external magnetic flux. The calculated persistent current, which arises from the nontrivial dependence of the ground state energy on the external flux, exists in isolated arrays without any periodic boundary condition. The sensitivity of the calculated persistent current to interaction and disorder is shown to reflect the intricacies of various Anderson-Mott-Hubbard quantum phase transitions in two dimensional systems.